Negative or vanishing edge for spas and/or hot tubs

A hot tub, comprising:

• (a) a relatively large recessed portion for holding users of said hot tub and water,
• (b) a first wall surrounding at least a first portion of said large recessed portion and extending upwardly a distance beyond the surface of maximum operating water quantity held in said hot tub,
• (c) a second wall surrounding a second portion of said large recessed portion, a top of said second wall ordinarily being beneath said surface of said water held by said large recessed portion under operating conditions, and allowing said water to flow over the top of said second wall during normal operation of said hot tub to form a vanishing edge,
• (d) a catch basin associated with said second wall to catch said water overflowing said top of said second wall, said catch basin being of a size considerably smaller than said large recessed portion, said catch basin having a catch basin wall with a top to retain said water overflowing from said second wall, said top of said catch basin wall being lower than a top of said second wall;
• and
• (e) a reservoir coupled to said catch basin to receive water flowing out of said catch basin being of a size to hold fluctuations in the water exiting from said large recessed portion into said catch basin when said water is displaced into said catch basin by users of said hot tub;
• (f) at least one pump return line between said reservoir and a pump operable to circulate said water within said hot tub;
• (g) a pump line between said pump and said large recessed portion to carry said water returned to said hot tub from said reservoir;
• (h) water exit orifices which return water to said hot tub;
• (i) a filter and a check valve between said pump and said jets;
• Wherein said hot tub is portable.